This invention relates to a novel thermal writing nib.
Thermal paper, that is paper that darkens in response to the application of heat, has been on the market for some time. Its most popular use is in copying machines where the thermal paper and the copy are placed in contact and a light is shined at the back of the copy. The light is absorbed by the writing on the copy and thus preferentially heats up writing areas to a temperature at which they are able to activate the thermal paper and thereby duplicate thereon the writing on the copy.
The ability to write directly on thermal paper with a pen could have wide beneficial applications in locations where a stand-by writing capability is required and where substantially instant start-up is desired. Such an application, could be for example Telautograph machines, which duplicate what is being written at one location at a distant location. These machines use pens, such as ball point pens. Problems with the ink drying up or the ball point sticking are experienced where stand-by, or non-use has occurred for an interval for time.
Heated styli presently available are not suitable for applications of the type mentioned, since substantially instant start-up is required with minimum power absorption. Presently available styli tips, of types such as are used in soldering irons, are usually heated inductively, or by thermal conduction. For applications of the type mentioned, besides a slower start-up than can be used, these thermally heated tips are wasteful of power.